The invention relates generally to the field of covers, housings or boxes for externally exposed pipes or conduits having valves, gauges, backflow preventors or the like, where the valves or other components need to be protected from ambient weather conditions, and in particular from freezes. More particularly, the invention relates to such devices where the cover includes access means, such as a door, panel or the like, to allow the valves to be operated, checked, repaired, etc. Even more particularly, the invention relates to such devices where the cover or housing is attached to the pipes or connecting flanges of the pipes themselves so as to be suspended above the ground surface, and further where the housing is divided into two major portions, where the complete upper portion of the housing is removable from the pipes without removal of the lower portion.
In many instances pipes or conduits containing a fluid susceptible to freezing, e.g., water, or excessive heat loss, e.g., steam, must have short segments of the pipeline exposed or removed from any insulating media to provide access to valves, gauges, reducers, backflow preventors, relief ports, or other like elements. For example, many pipelines will be buried underground except for short, inverted, U-shaped segments which are positioned above ground for access. The valves or other elements are oddly shaped in comparison to the tubular configuration of the pipeline and often extend at angles from the central axis of the pipeline. It is necessary or at least beneficial in many instances to provide an external housing or cover, often insulated, which encompasses the valves or other elements to protect them from damage and exposure to the extreme conditions. The housings are either supported by the ground, floor, slab or other base member, or are attached to the pipes themselves and suspended above the ground. Examples of such housings may be seen in U.S. Pat. No. 4,890,638 to Davenport, which shows a ground supported housing having a removable upper lid, U.S. Pat. No. 1,690,461 to Sieben, showing a box mounted onto the pipeline with a removable front and bottom wall member, and U.S. Pat. No. 5,522,420 to Martin, showing a housing having a removable top panel with the housing attached to the pipeline itself and having mounting means to attach the housing to a support base. Another solution to the problem of exposed valves is shown in U.S. Pat. No. 3,724,491 to Knudsen et al., which utilizes an insulating shell mounted directly onto the pipeline about the flanges, where the cover is customized to mate with the particular valve configuration being covered. Obviously, the latter solution suffers from the need to customize each cover to the particular application, a problem not encountered with the box-like housings shown in the other patents. The ground or base supported housing suffers the drawback of requiring the housing to be of greater overall size and volume than is required merely to provide protection for the valves, thus reducing the insulating efficiency of the housing and requiring an increase in material construction costs, as well as occupying an area on the ground beneath the valves which could otherwise be utilized for other purposes. The known pipeline mounted housings suffer from one or both of two major drawbacks--the lack of access space, especially where relatively small panels or doors are used, for operating or repairing the valves, and the need in many instances to remove the entire housing from the pipeline to obtain access to the valves.
It is an object of this invention to provide a valve housing or cover which occupies a relatively minimal amount of space necessary to provide protection to the valves or other elements of a pipeline exposed to ambient conditions, which is attached directly to the pipeline such that it is suspended above the ground or base surface, and which has a removable component which provides a maximum amount of access to the valves without the need for removing the entire housing from the pipeline. The housing may have various other features to increase the efficiency and usefulness of the device, such as insulation means or internal heating means. These and other objects are accomplished, as explained in detail below, by providing a valve housing having a lower portion connected directly to the pipeline or connecting flanges on either side of the valves, where the lower portion does not extend substantially above the pipeline, and an upper portion which is completely removable from the lower portion, the upper and lower portion being preferably insulated and joined together in a watertight manner.